The genus Capsicum comprises richness in morphological and genetic aspects. Studies of genetic diversity about this kind of genus are necessary to a further understanding about species, besides discoveries about new information in Capsicum germplasm banks. This study aimed to analyze the genetic variability of three species of Capsicum (9 accessions) from the Active Germplasm Bank of the Federal University of Piaui (BAGC). We used the technique of isozyme electrophoresis in starch gel for the analysis of five isozyme systems (ACP, GPI, IDH, MDH and PGM). As a result seven enzymatic loci and 13 alleles were detected, considering that, five alleles were exclusive, three were in the C. annuum var. glabriusculum (Gpi(c), Idh(a) and Acp(b)) sample, and the others were found in the C. baccatum var. pendulum (Pgm-1(b) and Pgm-2(b)) sample. All samples had polymorphic loci. The average number of alleles per locus varied between 1.4286 and 1. The calculated identities and Nei (1972) genetic distance showed a differentiation among the species. The constructed UPGMA dendrogram showed that the samples were grouped into two sets: C. annuum var. glabriusculum + C. chinense and C. baccatum var. pendulum. Therefore we concluded that the genetic diversity in the analyzed accessions is low and the methods used in this study are effective to differentiate species of Capsicum, proving the great diversity present in the genus Capsicum.
O gênero Capsicum compreende um rico gênero em aspectos morfológicos e genéticos. Estudos de diversidade genética ligada a este gênero são necessários para maior compreensão sobre as espécies, além de descobertas sobre novas informações em bancos de germoplasma de Capsicum. Este trabalho teve como objetivo analisar a variabilidade genética de três espécies do Capsicum (9 acessos) oriundas do Banco Ativo de Germoplasma da Universidade Federal do Piauí (BAGC). Para isso, utilizou-se da técnica de eletroforese de isoenzimas em gel de amido para a análise de cinco sistemas isoenzimáticos (ACP, GPI, IDH, MDH e PGM). Foram detectados sete loci enzimáticos e 13 alelos, sendo que cinco alelos foram exclusivos, três presentes na população de C. annuum var. glabriusculum (Gpi(c), Idh(a) e Acp(b)) e os demais na população de C. baccatum var. pendulum (Pgm-1(b) e Pgm-2(b)). Todas as populações apresentaram loci polimórficos. O número médio de alelos por locus variou entre 1,4286 e 1. As identidades e as distâncias genéticas de Nei (1972) calculadas demonstraram uma diferenciação entre as espécies. O dendrograma de UPGMA construído demonstrou que as populações foram agrupadas em dois conjuntos: C. annuum var. glabriusculum+C. chinense e C. baccatum var. pendulum. Concluímos portanto, que a diversidade genética dos acessos analisados é baixa e que os métodos utilizados nesta pesquisa são eficazes na diferenciação de espécies de Capsicum, comprovando assim a grande diversidade presente no gênero Capsicum.
Allozyme electrophoresis was used to examine 12 enzymatic systems in two populations of the genus Neoplecostomus from the Paraná River basin. Samples of Neoplecostomus sp. 1 were collected in Paraitinguinha stream of the Tietê River basin, in the municipality of Salesópolis, São Paulo State, and those of Neoplecostomus sp. 2 from São Domingos stream of the Rio Grande River basin, in the municipality of Muzambinho, Minas Gerais State. The genetic variability of the two populations was estimated by Nei's expected heterozygosity and was considered lower than average for populations of freshwater fish. The proportion of polymorphic loci was low (only 5.26% for the locus Idh). The low frequency of heterozygosity for both populations revealed a high fixation of alleles for each locus. Homozygote excess was observed in both populations. The values of Nei's genetic identity and the presence of loci with different allele frequencies in both populations may imply that the two populations belong to different species. The genetic variability between populations was compared to other data for loricariids.
Four samples of Neoplecostomus yapo were analyzed through the allozyme electrophoresis technique in corn starch gel. The allozyme pattern was similar to those found in N. paranensis with 24 loci scored. Two samples (ribeirão Atlântico and ribeirão Uraí) showed monomorphic bands for all 24 loci, whereas the other two (rio Verde and rio Fortaleza) showed 8.3% of polymorphic loci. The He genetic variability estimates for the rios Verde and Fortaleza populations were 0.0195 and 0.0179, respectively, too much inferior to the mean heterozygosity summed to species from the whole world (0.051). The Wright statistical values F IS = 0.5181, F IT = 0.5681 and F ST = 0.1039 and the genetic distance of Nei values showed that the four samples are genetically very similar to each other and that there is homozygote excess in the polymorphic loci.
Foram analisadas quatro populações de Neoplecostomus yapo por meio da técnica de eletroforese de aloenzimas em gel de amido de milho. O padrão de bandas obtido foi semelhante ao de N. paranensis, tendo sido detectado um total de 24 loci enzimáticos. Duas populações (ribeirão Atlântico e ribeirão Uraí) apresentaram formas monomórficas para todos os 24 loci, enquanto as outras duas (rio Verde e rio Fortaleza) apresentaram 8,3% de loci polimórficos. As estimativas de variabilidade genética He para as populações dos rios Verde e Fortaleza foram 0,0195 e 0,0179, respectivamente, muito inferiores à média das espécies de peixes no mundo todo (0,051). Os valores das estatísticas de Wright F IS = 0,5181, F IT = 0,5681 e F ST = 0,1039 e os valores de distância genética de Nei mostram que as quatro populações são geneticamente muito semelhantes entre si e que há excesso de homozigotos nos loci polimórficos.
Two syntopic morphotypes of the genus Hypostomus - H. nigromaculatus and H. cf. nigromaculatus (Atlântico Stream, Paraná State) - were compared through the allozyme electrophoresis technique. Twelve enzymatic systems (AAT, ADH, EST, GCDH, G3PDH, GPI, IDH, LDH, MDH, ME, PGM and SOD) were analyzed, attributing the score of 20 loci, with a total of 30 alleles. Six loci were diagnostic (Aat-2, Gcdh-1, Gpi-A, Idh-1, Ldh-A and Mdh-A), indicating the presence of interjacent reproductive isolation. The occurrence of few polymorphic loci acknowledge two morphotypes, with heterozygosity values He = 0.0291 for H. nigromaculatus and He = 0.0346 for H. cf. nigromaculatus. F IS statistics demonstrated fixation of the alleles in the two morphotypes. Genetic identity (I) and distance (D) of Nei (1978) values were I = 0.6515 and D = 0.4285. The data indicate that these two morphotypes from the Atlântico Stream belong to different species.
Two allopatric morphotypes of the genus Rinelocaria were compared through the allozyme electrophoresis technique: one morphotype, R. pentamaculata, from the Keller River in the middle stretch of the Ivaí River basin and the other, R. aff. pentamaculata, from the São João River in the upper portion of the Ivaí River basin. The morphotype from the São João River was collected upstream from the São João waterfall, which is about 80 m deep. Twelve enzymatic systems (AAT, ADH, EST, GCDH, G3PDH, GPI, IDH, LDH, MDH, ME, PGM and SOD) were analyzed, which allowed to score 22 loci. Only loci Aat-2, Est-3 and Mdh-C showed polymorphism. The two samples differed in allele frequencies at the three polymorphic loci. The average expected heterozygosity for all loci was 0.0806 ± 0.0447 in the Keller River sample. For the São João River morphotype, this value was 0.0489 ± 0.0350. Nei' s genetic identity and distance between the two populations were respectively 0.9789 and 0.0213. Wright's F IS, F IT and F STover all loci were estimated as 0.3121, 0.4021 and 0.1309, respectively. We consider that the two morphotypes represent species in statu nascendi.
The genetic variability of three Gymnotus species from the Caracu stream, a small tributary of the left margin of Paraná River (Brazilian upper Paraná River floodplain), was estimated with data of 17 putative allozyme loci, which were obtained by using corn starch gel electrophoresis of 10 enzymatic systems: Aspartate aminotransferase (E. C. 22.214.171.124), Alcohol dehydrogenase (E. C. 126.96.36.199), Esterase (E. C. 188.8.131.52), Glucose dehydrogenase (E. C. 184.108.40.206), Glycerol-3-phosphate dehydrogenase (E. C. 220.127.116.11), Isocitrate dehydrogenase (E. C. 18.104.22.168), L-Lactate dehydrogenase (E. C. 22.214.171.124), Malate dehydrogenase (E. C. 126.96.36.199), Superoxide dismutase (E. C. 188.8.131.52) and Sorbitol dehydrogenase (E. C. 184.108.40.206). The genetic diversity was estimated as He = 0.3458 for G. pantanal, He = 0.2481 for G. inaequilabiatus, and He = 0.3152 for G. sylvius. The most divergent species were G. sylvius and G. pantanal (D = 0.117), and the most similar were G. inaequilabiatus and G. pantanal (D = 0.051). The data indicates that the observed genetic variability was very low and the expected variability estimated for these three species is very high, and the genetic differences among them are small. The data suggest that the process of speciation which produced these three species is recent.
A variabilidade genética de três espécies de Gymnotus do riacho Caracu, um pequeno afluente da margem esquerda do rio Paraná (planície de inundação do alto rio Paraná) foi estimada com base em 17 loci aloenzimáticos, os quais foram obtidosutilizando eletroforese em gel de amido de milho em 10 sistemas enzimáticos: Aspartato aminotransferase (E. C. 220.127.116.11), Álcool desidrogenase (E. C. 18.104.22.168), Esterase (E. C. 22.214.171.124), Glicose desidrogenase (E. C. 126.96.36.199), Glicerol-3-fosfato desidrogenase (E. C. 188.8.131.52), Isocitrato desidrogenase (E. C. 184.108.40.206), L-Lactato desidrogenase (E. C. 220.127.116.11), Malato desidrogenase (E. C. 18.104.22.168), Superóxido dismutase (E. C. 22.214.171.124) e Sorbitol desidrogenase (E. C. 126.96.36.199). A diversidade genética foi estimada em He = 0.3458 para G. pantanal, He = 0,2481 para G. inaequilabiatus, e He = 0,3152 para G. sylvius. As espécies mais divergentes foram G. sylvius e G. pantanal (D = 0,117), e as mais semelhantes foram G. inaequilabiatus e G. pantanal (D = 0,051). Os dados mostram que a variabilidade genética observada é muito baixa, mas a esperada é muito alta e que as diferenças genéticas entre elas são pequenas. Os dados sugerem que o processo de especiação que originou as três espécies é recente.
Three Brazilian populations of the armored catfish Hypostomus regani (Ihering, 1905) were sampled, one from the Corumbá Reservoir in Goiás state, another from the Itaipu Reservoir in Paraná state and a third from the Manso Reservoir in Mato Grosso state. Allozyme electrophoresis was used to establish the genetic structure of the species, with the analysis of liver, heart and muscles tissues allowing the scoring of 25 loci from 14 enzymatic systems. Although no diagnostic loci were found, some exclusive rare alleles were recorded for the three populations. The genetically most similar populations were those from Corumbá and Itaipu, and the most distant were the populations from Manso and Corumbá. The allozyme data showed three structured populations belonging to the same species H. regani (F ST = 0.173).
We estimated the genetic variability of nine fish species from the Brazilian upper Paraná River floodplain (Astyanax altiparanae, Hoplias malabaricus, Leporinus lacustris, Loricariichthys platymetopon, Parauchenipterus galeatus, Pimelodus maculatus, Rhaphiodon vulpinus, Roeboides paranensis and Serrasalmus marginatus) based on data for 36 putative allozyme loci obtained using corn starch gel electrophoresis of 13 enzymatic systems: aspartate aminotransferase (EC 188.8.131.52), acid phosphatase (EC 184.108.40.206), esterase (EC 220.127.116.11), glycerol-3-phosphate dehydrogenase (EC 18.104.22.168), glucose-6-phosphate dehydrogenase (EC 22.214.171.124), glucose-6-phosphate isomerase (EC 126.96.36.199), Iditol dehydrogenase (EC 188.8.131.52), isocitrate dehydrogenase - NADP+ (EC 184.108.40.206), L-lactate dehydrogenase (EC 220.127.116.11), malate dehydrogenase (EC 18.104.22.168), malate dehydrogenase-NADP+ (EC 22.214.171.124), phosphoglucomutase (EC 126.96.36.199) and superoxide dismutase, (EC 188.8.131.52). The mean expected heterozygosity varied from zero to 0.147. When data from the literature for 75 species of tropical fish were added to the nine species of this study, the heterozygosity values differed significantly among the groups of different reproductive strategies. The highest mean heterozygosity was for the non-migratory without parental care, followed by the long-distance migratory, and the lowest mean was for the non-migratory with parental care or internal fecundation.
Allozyme data was used to assess the genetic diversity Astyanax altiparanae populations from the floodplain of the Upper Paraná River (PR). Specimens were collected in the southern Brazilian state of Paraná from PR in Porto Rico municipality and Ribeirão Ficha (RF) in Ubiratã municipality. The authors used 15% (w/v) corn starch gel electrophoresis to identify 21 putative loci for 13 enzymatic systems: Aspartate aminotransferase, 184.108.40.206 (AAT), Acid phosphatase, 220.127.116.11 (ACP), Esterase, 18.104.22.168 (EST), Glycerol-3-phosphate dehydrogenase, 22.214.171.124 (G3PDH), Glucose-6-phosphate dehydrogenase, 126.96.36.199 (G6PDH), Glucose-6-phosphate isomerase, 188.8.131.52 (GPI), Iditol dehydrogenase, 184.108.40.206 (IDDH), Isocitrate dehydrogenase - NADP+, 220.127.116.11 (IDH), L-Lactate dehydrogenase, 18.104.22.168 (LDH), Malate dehydrogenase, 22.214.171.124 (MDH), Malate dehydrogenase - NADP+, 126.96.36.199 (MDHP), Phosphoglucomutase, 188.8.131.52 (PGM), and Superoxide dismutase, 184.108.40.206 (SOD). The proportion of polymorphic loci were estimated as 52.38% in the PR population and 38.10% in the RF population. Expected estimated heterozygosities were 0.1518 ± 0.0493 for the PR population and 0.0905 ± 0.0464 for the RF population. The A. altiparanae heterozygosity data were similar to previous estimates for other PR basin characid species. Allele frequencies were significantly different between the PR and RF populations in respect to some loci (Acp-1, G3pdh-1, Gpi-A, Iddh-1, Mdhp-1 and Mdhp-2). Wright’s statistics for all loci were estimated as Fis = 0.3919, Fit = 0.4804 and Fst = 0.1455. Our results show that the A. altiparanae populations studied are genetically different and have a high degree of genetic variability.
Hypostomus strigaticeps and two morphotypes of Hypostomus were collected from Ribeirão Maringá, a small tributary of the Rio Pirapó, an effluent of the upper Rio Paraná. The three populations were analyzed by allozyme electrophoresis that allowed the scoring of 25 loci from 14 enzyme systems. Heterozygosity values (He) were 0.028 in H. strigaticeps, 0.027 in Hypostomus sp. 1 and zero in Hypostomus sp. 2. Several diagnostic loci and fixed differences were observed for each population at loci Acp-A, Gcdh-A and Mdhp-A. Thus, all populations were genetically distinct, although there were many common alleles. The unbiased genetic identities of Nei (I) were estimated as 0.780 for Hypostomus sp. 1 and H. strigaticeps, 0.357 for H. strigaticeps and Hypostomus sp. 2 and 0.322 for Hypostomus sp. 1 and Hypostomus sp. 2. The data indicate that the two morphotypes are distinct species from Hypostomus strigaticeps.
Samples of Crenicichla iguassuensis and a morph from the Iguaçu River which differed from C. iguassuensis by its lips morphology were examined by isozyme starch electrophoresis technique. The analysis of 27 enzyme loci exhibited a genetic identity of 0.993 between the two morphs. No diagnostic locus was found that permitted to distinguish the two Crenicichla morphs. The data obtained in this investigation did not support the existence of two distinct species for this genus in the Iguaçu River, which suggested that the morphs stood for two polymorphic forms of Crenicichla iguassuensis.
Amostras de Crenicichla iguassuensis e de um morfótipo do rio Iguaçu que difere de C. iguassuensis pela morfologia dos lábios foram analisadas pela técnica da eletroforese de isozimas em gel de amido. A análise de 27 loci enzimáticos revelou uma identidade genética de 0,993 entre as duas formas. Não foi encontrado nenhum locus diagnóstico que permitisse diferenciar os dois morfótipos de Crenicichla. Os dados obtidos nesta pesquisa não apóiam a existência de duas espécies distintas do gênero Crenicichla no rio Iguaçu. Os dados sugerem que as duas formas representam um polimorfismo da espécie Crenicichla iguassuensis.
The existence of reproductive isolation between two morphs of catfish, endemic to the Iguaçu River (Brazil), was examined by enzyme starch gel electrophoresis. Tissues of 19 catfish (Pimelodus ortmanni) and 15 of a similar morph (Pimelodus sp.), which differs from P. ortmanni by presenting larger and more scattered dusky spots on its skin, were analyzed. A Nei's (1978) genetic identity of 0.551 was determined by the analysis of 22 enzyme loci. The loci EST*1, EST*2, GDH*1, GPI*1, GPI*2, IDH*1, MDH*1, MDH*2, and PGM*1 were fixed for different alleles in each morph, that is, no heterozygote was found for these loci. The enzymatic patterns observed for the two morphs indicate both that the taxa are reproductively isolated and that they in fact represent separate species.
Eletroforese de enzimas em gel de amido foi utilizada para verificar a existência de isolamento reprodutivo entre duas formas de mandi endêmicas do Rio Iguaçu (Brasil). Foram analisados tecidos de 19 mandis (Pimelodus ortmanni) e 15 de uma forma semelhante (Pimelodus sp.), que difere de P. ortmanni por apresentar manchas escuras maiores e mais espaçadas sobre a pele. A análise de 22 locos enzimáticos exibiram uma identidade genética de 0,551. Os locos EST*1, EST*2, GDH*1, GPI*1, GPI*2, IDH*1, MDH*1, MDH*2 e PGM*1 se mostraram fixos para alelos alternativos em cada forma, isto é, nenhum heterozigoto para estes locos foi encontrado. Os padrões enzimáticos das duas formas indicaram que elas são reprodutivamente isoladas e que elas representam, de fato, duas espécies separadas.
The genetic variability of the "curimba", Prochilodus lineatus, from three locations in the Paraná river basin, was investigated by starch gel electrophoresis. A total of 160 specimens were analyzed for 19 enzymes, 12 of which permitted successful interpretation of electrophoretic patterns. Eighteen loci were identified and six of them proved to be polymorphic (EST-1*, EST-2*, IDH-1*, PGM-1*, PGM-2*, LDH-2*). Mean heterozygosity was considered high (13%) by comparison with the literature. A low level of differentiation was found among subpopulations, with mean F ST = 0.018. Values of genetic distance and genetic identity suggest that, at least along this stretch of the river, P. lineatus comprises a single breed with high gene flow. This analysis has important implications for fishery management, aquaculture, and conservation of the stocks
A variabilidade genética das subpopulações de curimba, Prochilodus lineatus, coletadas em três localidades da bacia do rio Paraná, foi analisada pela eletroforese em gel de amido. Um total de 19 sistemas enzimáticos foram analisados, em 160 indivíduos, dos quais 12 apresentaram padrões eletroforéticos interpretáveis geneticamente. Dos 18 loci identificados, seis mostraram polimorfismo (EST-1*, EST-2*, IDH-1*, PGM-1*, PGM-2*, LDH-2*). A heterozigose média de 13% foi considerada alta quando comparada com os dados da literatura. Um baixo nível de diferenciação foi encontrado entre as subpopulações, com F ST = 0,018. Os valores de distância e identidade genética sugerem que, ao menos neste trecho da planície de inundação, P. lineatus representa uma única unidade reprodutiva com alto fluxo gênico. Esta análise tem importantes implicações para o manejo de pesca, piscicultura e conservação dos estoques